Details for Benchmark: DX3086
N 33° 56.917 W 117° 52.117 (NAD 83)
Coordinates may not be exact. Altitude is READJUSTED and location is SCALED. (more info)
- In LOS ANGELES county, CA View Original Datasheet
- W 348
- Marker Type:
- survey disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1949 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1949
1.6 MI N FROM BREA. 0.77 MILE NORTHEASTERLY ALONG BREA BOULEVARD FROM ITS INTERSECTION WITH TONNER CANYON ROAD, 31 FEET SOUTHEAST FROM THE CENTERLINE OF BREA BOULEVARD, 60 FEET NORTHEAST OF A TELEPHONE POLE NUMBER 788929H, REFERENCED BY A METAL POST, 1.5 FEET SOUTHWEST OF THE REFERENCE METAL POST, SET ON A 1 FOOT BY 1 FOOT CONCRETE MONUMENT 5 INCHES ABOVE THE GROUND AND 5 FEET BELOW THE LEVEL OF THE ROADWAY.
|01/01/1970 by LAHSCH (GOOD)
|RECOVERY NOTE BY LOS ALTOS HIGH SCHOOL 1970
RECOVERED IN GOOD CONDITION.
|01/01/1978 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1978
0.2 MILES NORTHEAST ALONG BREA CANYON ROAD FROM THE LOS ANGELES- ORANGE COUNTY LINE, 85 FT. SOUTHWEST OF BM V 348, 381 FT. NORTHEAST OF 62 N=MWDSC, 5.5 FT. NORTHWEST OF OLD WIRE FENCE, 32 FT. SOUTHEAST OF THE CENTER LINE BREA, 2.0 FT. SOUTHWEST OF COUNTY WITNESS POST, 40 FT. NORTHEAST OF NORTHEAST END OF NEW FENCE, 61 FT. NORTHEAST OF POWER POL NUMBER 788929 H.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in February 1993. * This is a READJUSTED BENCH MARK height. Code E indicates a distribution rate of 4.1 thru 8.0 mm/km. The height was derived from older observations constrained to new heights in a crustal motion area. The height is approximate in relation to other heights in its vicinity.
- The geoid height was determined by GEOID99.
- The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (G = 980.6199 gals.).
- The modeled gravity was interpolated from observed gravity values.